Elevator-door guard.



-L. GHRISTIANSEN. ELEVATOR DOOR GUARD. APPLIOATION FILED NOV. 27, 1908.

Patented June 22, 1909.

"m: uamus PETERS 5a., wnmlvcwn.

LUDWIG GHRISTIANSEN, OF LYNN, MASSACHUSETTS.

ELEVATOR-DOOR GUARD.

Specification of Letters Patent.

Application filed November 27, 1908.

Patented Jane 22, 1909.

Serial No. 464,743.

To all whom it may concern:

Be it known that I, LUDwIe CHRISTIAN- SEN, citizen of the United States, residing at Lynn, in the county of Essex and State of Massachusetts, have invented certain new and useful Improvements in Elevator-Door Guards; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

The invention relates to elevator door guards such as are used in connection with freight elevators to prevent accidental entrance into the elevator well when the elevator is not in position at the door or opening where the guard is located.

One form of door guard which has been extensively used consists of a rigid bar pivoted at one side of the door or entrance into the elevator well so that it normally extends horizontally across the doorway, but may be swung up out of the way to give free access to the elevator well. Such pivoted bars cannot, however, be used in many places where the elevator door is wide as compared with the overhead space above the guard, since under such conditions there is not overhead space enough to allow the guard to be swung up out of the way.

It is one object of the present invention to provide animproved construction of extensile door guard which may be utilized in places where the space to be spanned by the guard when in position is large as compared to the free space over the pivotal support of the bar.

To this end one feature of the invention contemplates constructing the bar in sections which are so connected that they may move longitudinally with relation to each other, and providing positively acting means whereby the sections are relatively moved to contract or shorten the bar as it is swung upward, and are relatively moved to extend or elongate the bar as it is swung down into position across the door or entrance to the elevator well.

The invention in its broader aspects con-' templates the employment of any suitable connections between the sections of the bar which will enable the sections to move longitudinally relatively to each other, and the provision of any suitable positively acting means for securing the relative movement of the sections to contract or shorten the bar as it swings upward, and to extend or elongate the bar as it swings downward. It is preferred, however, to construct the bar of two or more telescoping sections arranged to slide one within the other, and to secure the contraction and extension of the sections by means of a link or similar connecting device one end of which is connected with the outer section of the bar, and the other end of which is connected at a oint below the pivot at the inner end of the ar.

The invention also contemplates the provision of improved means for retaining the guard bar in elevated position in case it is swung up out of the way when the elevator is in position at the door or entrance to the elevator well, and which is inactive whenever the elevator is not in position at the door.

The invention also contemplates the provision of improved means for retarding the fall of the guard bar when it is released from the holding means by the movement of the elevator away from the door. 7

The various features of the invention will be readily understood from an inspection of the accompanying drawings, in which Figure 1 is a front elevation partly in section of an elevator door guard embodying the features of the invention in the forms in which I prefer to use them, and Fig. 2 is a side elevation on an enlarged scale looking toward the right in Fig. 1.

In the construction shown in the drawings, the guard for the elevator door comprises a guard bar consisting of an inner section 1 and an outer section 2 arranged to slide within the section 1. The inner end of the section 1 is secured in a'block 3 which is supported upon a pivot 4 in the upper end of a sup orting standard 5. The supporting standarc 5 is secured at one side of the door or entrance to the elevator well, and the bar when in normal position extends horizontally across the entrance to the elevator Well, and is supported and confined at its outer end by a supporting bracket 6 secured at the opposite side of the doorway or en trance to the elevator well. The outer section 2 of the guard bar is pivotally connected to one end of a link 7, the other end of which is pivoted at 8 to the standard 5. The pivot 8 for the inner end of the link 7 is arranged below the pivot 4 for the bar, so that when the bar is swung up into the dotted line position, Fig. 1, the section 2 is drawn into the section 1, thus contracting or shortening the bar, and when the bar is swung down into the full line position, is drawn out of the section 1, thus extending or elongating the bar. By reason of this contraction and er;- tension of the bar as it is swung about its pivot, the bar may be utilized under conditions where there would otherwise be insutlicient space above the pivot of the bar to enable the bar to be swung into a vertical position.

The means for latching or holding the bar in position when it is swung up to give access to the elevator comprises a latch block 9 secured to the upper end of a vertical we" 10, and provided with a lip 11 which is adapted to engage a shoulder 12 on the block 3 when the bar is swung into the dotted line position, Fig. 1. The latch block is arranged to ride on a segmental surface 13 formed on the block 3, and is pressed upward by a spring 14 interposed between a lug 15 through which the rod 10 slides, and a collar 16 secured to the rod. In order that the latch may be rendered inactive whenever the elevator is not in position at the doorway or entrance which is guarded by the guard bar, a weight 17 is mounted to slide on the rod 10, and is arranged to normally rest upon the collar 16 and hold the latch block 9 away from the block 3 against the tension of the spring 14. This weight is connected by a chain 18 with a slide rod 19 which is mounted in the standard 5, and has its inner end arranged to project into the elevator well. The chain passes over the guide pulleys 20 and 21, and is connected to the slide rod 9 by means of a sleeve 22. The sleeve 22 carries a yoke 23, the arms of which engage opposite sides of a guide bar 24 and prevent turning of the rod 19. The inner end of the rod is provided with a roll 25 arranged to be engaged by a cam 26 carried by the elevator car.

lVhen the elevator car is not in position at the door across which the guard bar extends, the weight 17 is supported upon the collar 16, and acts to render the latching block 9 inactive. It the guard bar is raised at such time, it will immediately fall upon being released. When the elevator car comes into position at the door, the cam 26 secured to the car rides against the roll 25, forcing the rod 19 in a direction to lift the weight 17 so that the latch block is free to move upward under the influence of the spring 1 1. The weight is held in this position so long as the elevator remains in position at the door, and if the guard bar is swung up at this time the lip on the latch block will engage the shoulder 12 on the bar and retain the bar in elevated position. When the car moves up or down, the cam 26 will ride away from the roll 25, allowing the weight 17 to fall, and thus disengaging the latch from the bar and rendering the latch inactive.

The bar will now immediately fall into lull line position across the doorway or entrance to the elevator well.

in order to insure the initial movement of the bar from its vertical position, so that the .falling of the bar into active position under the force of gravity may be insured, I prefer to provide a spring 27 so arranged that it tends to swing the bar about its pivot when the bar is in its vertical position. This spring may be conveniently arranged within the section 1 as shown, so that it is engaged and compressed by the inner end or" the section 2 when the parts are in the dotted line position, Fig. 1. When the bar is released by the latch block, the tension of this spring tends to force the section 2 upward, and puts a tension on the link 7 so that the bar is swung about its pivot. As soon as the bar is given an initial movement toward the right in Fig. 1, the Weight of the bar will act to insure the swinging of the bar down into horizontal position.

In order that the fall of the bar may be retarded so that it will swing into active position without shock or injury to the parts, a restricted communication between the interior of one of the telescoping sections and the atmosphere is provided which regulates the flow of air as the bar falls, and thus prevents the rapid fall of the bar. In the construction shown, the restricted communication for the flow of air consists of a small vent 28 formed in the block 3 at the inner end of the outer section 1 or" the bar. The How of air through this vent may be regulated by an adjustable valve screw 29. In order that the fall of the bar may be accurately regulated, the inner end of the outer section 2 may be provided with a packing 30 to pre vent the escape of air between the inner and outer sections as the inner section moves outward during the fall of the bar. In order that the air confined within the outer section 1 may not unduly interfere with the upward movement of the bar, I prefer to provide a passage 31 through the inner end of the outer section 2, and to provide a valve 32 which will act to automatically close the passage during the outward movement of the section 2. When the bar is swung upward, the air within the outer section 1 may escape through the vent 28 and through the passage 31, so that the bar may be readily swung upward into its vertical position. When the bar swings downward, however, the ball valve 82 will automatically close the passage 31, so that the only communication between the interior of the section 1 and the atmosphere is through the vent 28. The rate at which the bar will fall, therefore, will depend upon the size of the vent 28, which may be regulated as desired by the valve is not essential, and may be varied as found desirable in constructing the telescopic sections so that they will form a pneumatic repoarding device for regulating the fall of the While I prefer to employ the specific arrangement and construction of parts shown and described, it will be understood that such construction and arrangement is not essential to the invention in its broader aspects, and may be varied and modified without departing from the invention.

Having explained the nature and object of the invention, and specifically described one form of device in which it may be embodied, what I claim is 1. A door guard for elevators comprising a guard bar adapted to be swung upward and downward, said bar consisting of sections connected for free relative longitudinal movement, a pivotal support for the inner end of the bar and a link connecting the outer section of the bar with a point below the pivotal support of the bar and acting to contract the bar as it swings upward and to extend it as it swings downward, substantially as described.

2. A door guard for elevators comprising a bar formed of telescoping sections, a pivotal support for one end of the bar, means for contracting the bar as it swings upward and extending it as it swings downward, and a restricted communication between the atmosphere and the interior of one of the sections for regulating the fall of the bar, substantially as described.

3. A door guard for elevators comprising a bar formed of telescoping sections, a ivotal support for one end of the bar, a ink connecting the other end of the bar with a point below the pivot of the bar, and a vent for regulating the communication between the outer telescoping section and the atmosphere to retard the fall of the bar, substantially as described.

4. A door guard for elevators comprising a bar, a spring operated latch for holding the bar in elevated position, a device for disengaging the latch and holding it normally out of action against the tension of the spring, and means operated by the elevator car for actuating said device to release the latch while the elevator car is at the door, substantially as described.

5. A door guard for elevators comprising a ivoted bar, a spring operated latch for ho ding the bar in elevated position, a weight arranged to render the spring inactive, a slide arranged to be operated by the elevator car, and connections between the slide and weight, substantially as described.

6. A door guard for elevators, comprising a pivoted bar, a latch for holding the bar in elevated position, a spring tending to render the latch operative, and means operated by the elevator car to render the spring active to force the latch into engagement with the bar when the elevator car is at the door and to render the spring inactive when the elevator car is not at the door, substantially as described.

7. A door guard for elevators comprising a bar formed of two telescoping sections, a pivotal support for one end of the bar, a link connecting the other end of the bar with a point below the pivot for the bar, and a spring arranged to force the sections apart when the bar is in its vertical position, sub- 7 stantially as described.

8. A door guard for elevators comprising two telescoping sections, a pivotal support for one end of the bar, means for contracting the sections as the bar swings upward and extending the sections as the bar swings downward, a vent for controlling communication between the outer section and the atmosphere, and a valve arranged to open communication between the outer section and the atmosphere during the upward movement of the bar and to close said communication during the downward movement of the bar, substantially as described.

In testimony whereof I affiX my signature, in presence of two witnesses.

LUDWIG CHRISTIANSEN.

Witnesses:

IRA L. FISH, ANNIE O. RICHARDSON. 

